Systems Analysis of CNS Stem Cells as Early-Stage Progression of Prion modef We are proposing to employ systems analysis to understand the biological networks containing the prion and prion-associated molecules using CNS stem cells developed by Dr. Carlson (Projectl). CNS neurosphere lines provide an excellent model system for dynamically following the course of the global changes in levels of mRNAs and proteins as well as changes in key protein/protein and protein/DNA interactions during the course of prion infection in several different inbred mouse strains. Global assays will be used to characterize the transcriptomes, proteomes, and the interactomes in normal and disease perturbed CNS stems cell. This will enable us to construct so-called subtracted perturbation networks. These prion- perturbed networkswill delineate the dynamics of the prion-infection process and will identify key molecules that play a role in the biological networks mediating prion disease. They will also help provide deep insights into the pathophysiology of prion infection. Moreover, these studies will provide a new frame work to identify early diagnostic biomarkers for prion infections.